I got this code in my custom block's class file:

 

package com.tominocz.PAYDAY2;
import net.minecraft.block.Block;
import net.minecraft.block.material.Material;
import net.minecraft.client.audio.PositionedSoundRecord;
import net.minecraft.client.audio.SoundHandler;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.util.ResourceLocation;
import net.minecraft.world.World;

public class LobbyBlock extends Block{

SoundHandler sh;

public LobbyBlock(Material rock) {
	super(rock);
	this.setBlockName("LobbyBlock");
	this.setBlockTextureName(Main.MODID + ":" + "0");
	this.setCreativeTab(Main.PAYDAY2Tab);
	this.setLightLevel(1F);
	this.setLightOpacity(2555);
}

@Override
public boolean onBlockActivated(World world, int x, int y, int z, EntityPlayer player, int par6, float par7, float par8, float par9)
    {
     if (world.isRemote)
        {
            return true;
        }
        else
        {
            //HERE I WANT THE CODE FOR OPENING MY CUSTOM GUI/HUD
    	    System.out.println("clicked");
            return false;
        }
    }
}

 

And I got this in the main class:

 

package com.tominocz.PAYDAY2;

import net.minecraft.block.Block;
import net.minecraft.block.material.Material;
import net.minecraft.creativetab.CreativeTabs;
import net.minecraft.item.Item;
import cpw.mods.fml.common.Mod;
import cpw.mods.fml.common.Mod.EventHandler;
import cpw.mods.fml.common.event.FMLInitializationEvent;
import cpw.mods.fml.common.event.FMLPostInitializationEvent;
import cpw.mods.fml.common.event.FMLPreInitializationEvent;
import cpw.mods.fml.common.registry.GameRegistry;

@Mod(modid = Main.MODID, version = Main.VERSION)
public class Main
{

    public static final String MODID = "PAYDAY2";
    public static final String NAME = "PAYDAY 2 RELOADED";
    public static final String VERSION = "0.01";
    
    public static CreativeTabs PAYDAY2Tab = new PAYDAY2Tab(MODID);
    public static Block LobbyBlock = new LobbyBlock(Material.rock);
    public static Item Logo = new PAYDAY2Logo();
    
    @EventHandler
    public void preInit(FMLPreInitializationEvent event)
    {
    	GameRegistry.registerBlock(LobbyBlock, "LobbyBlock");
    	GameRegistry.registerItem(Logo, "Logo");
    }
    
    @EventHandler
    public void Init(FMLInitializationEvent event)
    {

    }
    
    @EventHandler
    public void postInit(FMLPostInitializationEvent event)
    {

    }
}

 

Now I need the code to open my custom gui/hud like when opening a chest or a crafting table..

but I also want to add buttons in there..

 

Is it possible?

Ok, thanks for information. I just hope I can make it . Because the block is the main thing.. without it.. you can't do anything in the mod .

Well, I haven't found any tutorial about GUI so far. Everything was a different video...

If you know, where I could find one, tell me please.

It works! Now it opens a gui with a text! But now there's an only problem.. it's not compatible with a server.. Do you know how to do that please?